JP2001059445A - Electronic governor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform correct and reasonable detection of a zero point. SOLUTION: The pulse number which corresponds to a rotation angle of a servo-motor 601 toward a zero-point position at which the fuel supply quantity to a main diesel engine 3, is counted by a counter 203, and the counted value by the counter 203 is taken in a position calculation and control device 204 every fixed time. These taken-in counted values are compared to the previous counted values, and a position at the time when the change in these counted value is smaller than a preset value k, is judged to be a zero-point position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic governor system for controlling the rotation speed of a marine diesel main engine.

[0002]

2. Description of the Related Art Conventionally, in a marine diesel main engine, an electronic governor system for automatically and optimally controlling the number of revolutions in an operating state has been used.

FIG. 3A shows an example of such an electronic governor system.
From the number of revolutions of the diesel main engine 3 per unit time (Q
rpm) to the control unit 2. on the other hand,
The actual number of revolutions (Prpm) of the diesel main engine 3 is obtained by counting the number of teeth of gears cut on the outer periphery of the flywheel 4 passing through the unit of time by the number of revolutions pickup 5.

The control unit 2 calculates a deviation between the command rotation speed (Qrpm) and the actual rotation speed (Prpm), and the PID control unit 201 determines the optimum position of the actuator 6 according to the deviation. It is output as a control command to the actuator drive unit 7 via 202. Here, the limiter 202 sets the operation upper limit position of the actuator 6 and regulates the fuel supply to the fuel pump 301 of the diesel main engine 3 so as not to exceed a set value, thereby preventing the diesel main engine 3 from being overloaded. At the same time, it is set so that the actuator 6 does not go below a predetermined position during normal operation. These settings are made by the operation panel 8.

The actuator 6 includes a servo motor 601
And a reduction gear 602 provided on the output shaft, an output shaft 603 connected to the reduction gear 602, and a brake 604 and a resolver 605 provided on the rear end side of the servomotor 601. In this case, when the servo motor 601 is in a normal operation state, the brake 604 is released.

[0006] When a command from the actuator drive unit 7 is input to the servomotor 601, the servomotor 601 is driven and rotated to change the angle of the output shaft 603. In this case, the output shaft 603 of the servo motor 601 is connected to the fuel pump 301 of the diesel engine 3 via the lever mechanism 9. The lever mechanism 9 fixes one end of the lever 901 to the output shaft 603, and fixes one end of the lever 903 to the input shaft 902 of the fuel pump 301.
A connecting lever 904 is rotatably connected to the other end of the actuator 1 and 903 via a pin 905, and the output shaft 603 of the actuator 6 and the input shaft 902 of the fuel pump 301 are simultaneously displaced by the same angle in the same direction at the same time. The fuel pump 301
The rotational speed of the diesel main engine 3 is increased / decreased by increasing / decreasing the fuel supply amount.

Thus, the main engine remote controller 1
The command speed (Qrpm) given by the command speed (Qrpm) and the actual speed (Prpm) of the diesel main engine 3 measured by the speed pickup 5 are given by
And the actual rotational speed (Prpm) is controlled so that the deviation of the rotational speed of the diesel main engine 3 becomes zero. At this time, the forward and reverse rotational displacement angle signals of the servo motor 601 are fed back to the actuator drive unit 7 by the resolver 605, converted into pulse signals, and based on a deviation value between the pulse signals and the command value of the PID control unit 201. When the servomotor 601 is driven, the output shaft 603
Is obtained as an integrated value of the pulse number.

In such an electronic governor system, the setting and control of the limiter 202 are performed based on a zero point (fuel supply: 0%), and the setting of the zero point is extremely important.

Therefore, such a zero point is set each time the system power supply (AC or DC) is turned on.
In the case where the brake 604 is actuated due to the occurrence of an abnormality and stops while maintaining the current state of the actuator 6, resetting is performed when returning the actuator 6, and after that, the setting is confirmed and the operation is started. The abnormal operation of the brake 604 here includes an abnormal operation of the control CPU, an abnormal operation of the control A / D converter, a rotational speed command or system abnormality, and switching from manual operation to automatic operation by the electronic governor system.

As shown in FIG. 3B, the lever 903 fixed to the input shaft 902 of the fuel pump 301 is rotated in the zero direction (counterclockwise in the figure) to set the zero point used for the zero point setting. At this time, the mechanical stopper 906 is disposed at a position where the fuel supply from the fuel pump 301 becomes zero, and a position where the lever 903 abuts on the mechanical stopper 906 and cannot rotate is set as a zero point. The amount of fuel supplied by the fuel pump 301 is determined based on the amount of rotational displacement in the illustrated clockwise direction.

Then, in order to detect the zero point position configured as described above, first, as shown in FIG.
01, when the system power is turned on, step S40
2, the brake release power is also turned on, and the brake 604 is turned on.
Is released, and in step S403, the zero point setting mode is set. In this state, in step S404, the servo motor 601 is rotated in the zero direction, and the lever 903 fixed to the input shaft 902 of the fuel pump 301 is rotated in the zero direction (counterclockwise in the figure). Then, step S405
Then, the state where the lever 903 comes into contact with the mechanical stopper 906 and cannot be rotated, and the current value I of the servomotor 601 suddenly increases is monitored. Here, when the current value I of the servomotor 601 exceeds a preset maximum value Imax, the lever 9
03 is determined to be incapable of rotation due to contact with the mechanical stopper 906, and subsequently, in step S406, when it is determined that this state has passed a preset holding time To, in step S407, the lever 903 in this state is determined.
Is recognized as a zero point, the zero point setting mode is canceled in step S408, and control of the electronic governor system is started in step S409.

[0012]

However, according to such a method of detecting the zero point, the servomotor 601 is rotated in the zero point direction, and the lever 903 is moved to the mechanical stopper 906.
Until it cannot rotate, and press the servo motor 6
Since a large current continues to flow through the P.01 for a predetermined time, there is a problem in that the operation is unreasonable, and it is difficult to maintain a stable operation for a long period of time.

The present invention has been made in view of the above circumstances, and has as its object to provide an electronic governor system capable of performing accurate and reasonable zero point detection.

[0014]

According to the first aspect of the present invention,
In an electronic governor system for controlling the rotation speed of a diesel main engine, a fuel supply amount to the diesel main engine is controlled by a rotation angle corresponding to a deviation between a command rotation speed and an actual rotation speed of the diesel main engine, and the diesel A servo motor for determining the number of revolutions of the main engine, counter means for counting the number of pulses corresponding to the rotation angle of the servo motor to a zero point position where the fuel supply amount to the diesel main engine is zero, and this counter means And a position calculation control unit that samples the count value at predetermined time intervals, compares the count value of the previous time with the count value of the previous time, and determines a position when a change in the count value becomes smaller than a preset value as a zero point position. It is characterized by having.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of an electronic governor system to which the present invention is applied.
The same reference numerals are given.

In this case, the control unit 2 includes:
A counter 203 that stores the rotation angle of the servomotor 601 as a count value and a position calculation control device 204 that determines a zero point using the count value of the counter 203 are provided. In this case, the position calculation control device 204 has a register 205 that temporarily stores the previous count value of the counter 203 sampled at a predetermined time interval.

The rest is the same as FIG.

Next, the operation of the embodiment configured as described above will be described.

In this case, the system power supply (AC or D
When C) is released under normal operation, or when the brake 604 is operated due to the occurrence of an abnormality and stops while maintaining the current state of the actuator 6, the levers 901 and 903 of the lever mechanism 9 are set to the mechanical stopper 906. And stopped at a predetermined position between the upper limit position.

In this state, when the system power supply (AC or DC) is turned on, zero point detection is executed from the above-mentioned stopped state.

In this case, in the flowchart shown in FIG. 2, when the stem power is turned on in step S201, the brake release power is also turned on in step S202, the brake 604 is released, and in step S203,
The zero point setting mode is set.

In this state, the process proceeds to step S204, where the count value PLn of the counter 203 and the stored value PR of the register 205 are reset, and are initialized to PLn = 0 and PR = 0, respectively.

Next, in step S205, the servo motor 601 is rotated in the zero direction, and the lever 903 fixed to the input shaft 902 of the fuel pump 301 is rotated in the zero direction (counterclockwise in the figure). In this case, the servo motor 601
Is detected by the resolver 605, and the analog signal output from the resolver 605 is converted into the number of pulses of the digital signal by the actuator drive unit 7, and the counter 203 of the control unit 2 corresponds to the rotation angle of the servo motor 601. The number of pulses is counted.

Then, in step S206, after a predetermined time (sampling time: several tens of msec) has elapsed, in step S207, the count value PLn of the counter 203 corresponding to the rotation angle of the servo motor 601 at this point. Is taken into the position calculation control device 204, and step S2
At 08, the detection of the zero point position is determined with reference to the previous count value PR stored in the register 205.

In this case, the position calculation control device 204 uses the count value sampled at a predetermined time interval as PL
1, PL2,..., PLn-1, PLn
When 01 rotates in the direction of the zero point, if these are determined to be in the negative direction, these count values PL1, PL2, ..., PLn-1, P
Ln is a negative integer value, and the absolute value of the current count value PLn is always larger than the previous count value PLn-1 as long as the rotation continues. From this, the result of the comparison between the previous count value and the present count value (PLn−1−PLn) is always a positive integer, but the lever 903 of the lever mechanism 9 is
When the rotation is stopped at 6, PLn−1 = PLn, that is, PLn−1−PLn = 0. Accordingly, the stop of rotation when the lever 903 hits the mechanical stopper 906 can be strictly determined by PLn−1−PLn = 0, but in reality,
Since play and elasticity exist in the control system, it is not preferable to determine the zero point position based only on this relationship. Therefore, a relatively small value K (K is a positive integer, for example, an integer such as 2 or 3) set in advance by experience or a test is set in advance.
When PLn-1−PLn becomes smaller than K, it is determined that the rotation has stopped. That is, since PLn-1−PLn <K, PLn−1 (PR) −PLn−K = 0 (1) is used as a criterion for zero point determination. Here, for convenience of explanation, the previous count value is described as PLn-1.
Actually, the count value PR stored in the register 205 is used.

In step S208, the position arithmetic control unit 204 determines whether the count value PLn taken for each sampling satisfies the condition of the expression (1). If the condition of equation (1) is not satisfied, the current count value PLn is stored in the register 205 as the previous count value PR in step S209, and n is incremented by n + 1 in step S210. Returning, the same operation as described above is repeated until the condition of equation (1) is satisfied.

Thereafter, when the lever 903 of the lever mechanism 9 comes into contact with the mechanical stopper 906 and the rotation of the servomotor 601 stops at an extremely low speed or stops and the condition of the expression (1) is satisfied, the position at this time becomes the zero position. Determined and set in the system.

Then, in step S211, the zero point setting mode is canceled and the mode is switched to the system control mode. In step S212, control of the electronic governor system is started.

Accordingly, in this case, the counter 203 counts the number of pulses corresponding to the rotation angle of the servo motor 601 toward the zero point where the fuel supply amount to the diesel main engine 3 is zero. The count value of 203 is taken into the position calculation control device 204 at fixed time intervals, and these taken-in count values are compared with the previous count value, and when the change of these count values becomes smaller than the preset value K, Since the position is determined as the zero point position, the lever is pressed until it stops rotating because it comes into contact with the mechanical stopper and the large current continues to flow to the servo motor for a predetermined time. In this state, zero point detection can be performed, and accurate and stable operation can be maintained for a long time. .

Since the sampling time of the count value to the position calculation controller 204 is as short as several tens of seconds, the determination of the zero point position after the lever 903 actually hits the mechanical stopper 906 can be performed in a short time. Thus, an overload on the servomotor 601 can be reduced.

[0032]

As described above, according to the present invention, the number of pulses corresponding to the rotation angle to the zero point position of the servomotor for determining the rotation speed of the diesel main engine is sampled at regular time intervals, and the previous and current times are sampled. Are compared with each other, and the position when the change in the count value becomes smaller than a preset value is determined to be the zero point position, so that accurate and reasonable zero point detection can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment;

FIG. 3 is a diagram showing a schematic configuration of a conventional electronic governor system.

FIG. 4 is a flowchart for explaining the operation of a conventional electronic governor system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main machine remote controller 2 ... Control unit 201 ... PID control part 202 ... Limiter 203 ... Counter 204 ... Position calculation control device 205 ... Register 3 ... Diesel main engine 301 ... Fuel pump 4 ... Flywheel 5 ... Rotation speed pickup 6 ... Actuator 601 servo motor 602 reduction gear 603 output shaft 604 brake 605 resolver 7 actuator drive unit 8 operation panel 9 lever mechanism 901.903 lever 902 input shaft 903 lever 904 connecting lever 905 pin 906 … Mechanical stopper

Continued on front page F-term (reference) 3G060 AC02 AC09 BA03 BA17 BA19 CA01 CB01 CC00 CC08 DA06 FA06 GA01 GA03 3G084 AA01 BA03 BA13 CA01 DA04 DA22 EA04 EA05 EA08 EA09 EA11 EB02 EB12 EC03 FA10 FA13 FA18 FA33 3G301 KA01 JA15 NA03 NA04 NA05 NA08 NB02 NB03 NB05 NC08 ND01 NE23 PA17Z PB04Z PE01A PE01Z

Claims (1)

[Claims] 1. An electronic governor system for controlling the rotation speed of a diesel main engine, wherein the amount of fuel supplied to the diesel main engine is determined by a rotation angle corresponding to a deviation between a command rotation speed and an actual rotation speed of the diesel main engine. A servo motor for controlling and determining the rotation speed of the diesel main engine; and a counter means for counting the number of pulses corresponding to the rotation angle of the servo motor to a zero position where the fuel supply amount to the diesel main engine is set to zero. The count value of the counter means is sampled at regular intervals, the previous count value and the current count value are compared, and the position when the change in the count value becomes smaller than a preset value is determined as the zero point position. An electronic governor system comprising: a position calculation control unit.